Derivatives - Cash Flow Hedges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net realized gains (losses)	$ 509	$ (14)	$ 395
Net investment income	2,313	1,846	1,951
Interest Expense	234	236	259
Interest rate swaps | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net realized gains (losses)	0	0	2
Net investment income	41	29	4
Interest Expense	(10)	(7)	1
Foreign currency swaps | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net realized gains (losses)	0	(1)	0
Net investment income	5	5	3
Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	28	30	26
Designated as Hedging Instrument | Cash Flow Hedging | Reclassification out of Accumulated Other Comprehensive Income | Gain (Loss) on Investments [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain Reclassified from AOCI into Income	0	(1)	2
Designated as Hedging Instrument | Cash Flow Hedging | Reclassification out of Accumulated Other Comprehensive Income | Foreign currency swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain Reclassified from AOCI into Income	46	34	7
Designated as Hedging Instrument | Cash Flow Hedging | Reclassification out of Accumulated Other Comprehensive Income | Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain Reclassified from AOCI into Income	(10)	(7)	1
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	4	38	18
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Gain (Loss) on Investments [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain Reclassified from AOCI into Income	0	0	2
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Foreign currency swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain Reclassified from AOCI into Income	41	29	4
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swaps | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain Reclassified from AOCI into Income	(10)	(7)	1
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax	24	(8)	8
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency swaps | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Gain (Loss) on Investments [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain Reclassified from AOCI into Income	0	(1)	0
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency swaps | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Foreign currency swaps
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain Reclassified from AOCI into Income	5	5	3
Designated as Hedging Instrument | Cash Flow Hedging | Foreign currency swaps | Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Interest Expense [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain Reclassified from AOCI into Income	$ 0	$ 0	$ 0